Die punch for sheet metal forming press

ABSTRACT

A die punch mounted upon the stationary bed of a sheet metal die forming press for piercing an opening through a vertical wall of the sheet metal workpiece while the formed workpiece still remains upon the bed part die during the upwards retraction stroke of the movable press ram following the ram down or workpiece forming stroke. The punch includes a support base fixed upon the press bed and a slider slidably mounted upon the base and having a punch element mounted upon its forward end for engaging the formed vertical wall. The slider is driven forwardly by a drive cam which is mounted upon the ram for movement therewith and which engages a cam member pivotally mounted upon the rear end of the slider. The cam member is pivoted out of the way by the drive cam during the movable ram down or forming stroke, so that the slider remains inoperative, i.e., unmoved, in its retracted position during the forming stroke. However, the cam member is driven forwardly by the drive cam during the ram upwards or retraction stroke, to thereby move the slider and operate the punch against the by now formed wall part of the workpiece.

taes Patent 1 Euteneuer et a1.

[ DIE PUNCH FOR SHEET METAL FORMING PRESS [76] Inventors: Fred Euteneuer, 32021 Claeys,

Warren, Mich. 48093; Detlef Mlarhurg, 11298 Afton, Southgate, Mich. 48195 [22] Filed: Aug. 8, 1973 [21] Appl. No.: 386,649

Primary Examiner-C. W. Lanham Assistant Examiner-James R. Duzan Attorney, Agent, or Firm--Cullen, Settle, Sloman & Cantor [4 1 Jan.7, 1975 [57] ABSTRACT A die punch mounted upon the stationary bed of a sheet metal die forming press for piercing an opening through a vertical wall of the sheet metal workpiece while the formed workpiece still remains upon the bed part die during the upwards retraction stroke of'the movable press ram following the ram down or workpiece forming stroke. The punch includes a support base fixed upon the press bed and a slider slidably mounted upon the base and having a punch element mounted upon its forward end for engaging the formed vertical wall. The slider is driven forwardly by a drive cam which is mounted upon the ram for movement therewith and which engages a cam member pivotally mounted upon the rear end of the slider. The cam member is pivoted out of the way by the drive cam during the movable ram down or forming stroke. so that the slider remains inoperative, i.e.. unmoved. in its retracted position during the forming stroke. However, the cam member is driven forwardly by the drive cam during the ram upwards or retraction stroke, to thereby move the slider and operate the punch against the by now formed wall part of the workpiece.

5 Claims, 10 Drawing Figures PATENTED 3. 858 .427

SHEET 1m a ILL 1 L N PATENTED JAN 7 I975 SHEET 1 DIE PUNCH FOR SHEET METAL FORMING PRESS BACKGROUND OF INVENTION It is customary in stamping or die forming sheet metal parts, such as for example, automotive body parts, to initially rough form the part in a first stamping press, and thereafter, where sharp corners, walls and the like are included in the part (e.g., such as in door or window panels, etc), to restrike the part in another press. At times, there may be serveral press operations to form a completed stamping or die formed part. Many of such type parts require the addition of punched holes or slots or notches or other types of recesses which are pierced through edge flanges or wallforming portions arranged roughly perpendicular to the plane of the workpiece body. Thus, after the restrike operation is completed, that is, after the final stamping or press steps'are completed, the workpiece is usually placed into a separate punching press for piercing the openings through the walls and flanges thereof. This, of course, necessitates additional handling, more labor, and additional machinery.

It would be desirable to perform the piercing operations in the walls or edges in the same press machinery which performs the final or restrike press or stamping operation upon the workpiece to thereby eliminate the additional piercing or punching steps. Thus, the invention herein is concerned with punching equipment which can be utilized upon a final stamping or restrike press and which will operate to pierce openings through walls and edge flanges of the stamped part after they are finally formed, but during the operation of the press to thereby eliminate further handling and equipment.

SUMMARY OF INVENTION The invention herein relates to a die punch for mounting within a stamping or die forming press, which includes a base for securement upon the base of the press, and a slide member carrying a punch on one end for piercing a wall of a completed stamping or workpiece during the retraction or'upward movement of the press ram. The slider is normally positioned with its punch retracted, away from the wall of the stamping. A drive member, connected to the movable press ram engages and pivots out of the way a pivotal cam member mounted upon the rear end of the slider, during the down stroke of the press ram when the workpiece is struck and formed between the press dies. On the upstroke or retraction of the ram, the drive member engages the cam member again, but this time forces the cam member and theslider upon which it is connected, to move in a punching direction. Thus, the punching stroke is performed upon a completed stamping, such as during the restrike stamping operation where a workpiece is completed within a press.

The die punch herein is a simply constructed, yet accurate, mechanically operated mechanism, requiring minimal maintenance, and operated by and during the retraction stroke of the press ram. Thus, its use eliminates subsequent handling and a subsequent piece of machinery for piercing holes of various types in the bent walls or flanges of a stamped workpiece, resulting in considerable economies in the production of the finished workpiece.

These and other objects and advantages of this invention will become apparent upon reading the following description, of which the attached drawings form a part.

DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view, in partial cross-section of a stamping or die forming press, with the ram or movable press part elevated.

FIG. 2 is a perspective view of "a stamped or die formed sheet metal part to illustrate the location of a hole formed by the die punch herein.

FIG. 3 is a perspective view of the die punch, per se.

FIG. 4 is a view similar to FIG. 3 but showing the slider member in its forward, punching or piercing position.

FIG. 5 is a perspective, disassembled view, of the die punch.

FIG. 6 is a perspective view of the slider and the cam member disassembled therefrom.

FIG. 7 isa crosssectional, elevational view, of the die punch with the drive member moving downwardly relative thereto.

FIG. 8 is a view similar to FIG. 'lshowing the engagement between the drive member and the cam member.

FIG. 9 is a view similar to FIG. 8, showing the drive member rising or moving upwardly and engaging the cam member.

FIG. 10 is an enlarged, fragmentary view of the cam member in two different positions.

DETAILED DESCRIPTION FIG. 1 schematically illustrates a conventional stamping or die forming press 10, comprising a fixed base or bed 11 upon which a lower die 12 is mounted.

A vertically movable ram or press part 13 is provided with an upper die 14 for cooperative mating with the lower die for forming a sheet metal workpiece 15 there between. The sheet metal workpiece in FIG. 1, is shown as completely formed, after the press operation, but before removal from the lower die.

Conventionally, in stamping sheet metal parts, such as automotive body parts, the sheet metal is placed upon a lower die in the press and upon the downstroke of the press ram, the upper die cooperates with the lower die to form the sheet metal. Frequently, this may be done several times, in different stages to make a final finished part. Alternatively, it may be done once and then a second timein what is called a restrike operation to finish the comers and dimensional accuracy of the once stamped sheet metal part.

The type of workpiece with which the invention herein is concerned is a type which has a bent up vertically arranged wall 16 or flange. Such a wall or flange is arranged normal or substantially normal to the main body of the sheet metal workpiece. In addition, the sheet metal workpiece typically has either an opening 17 or is so made as to be open adjacent to the wall or flange. By way of example, an automobile window frame part would be of the general type of part involved.

The die punch unit 20 is mounted upon the lower die or upon the bed of the press and arranged to pierce or punch an opening in the wall or flange 16 of the workof a bottom support wall bounded by side guide walls 26 upon which cover strips 27 are arranged to form ways or channels. The cover strips may be fastened to the side guide walls by long machine screws 28 which pass completely through the walls and may be engaged with the press bed or lower die for firmly securing the support base thereon. Alternatively, other mechanical fasteners may be used to fix the support base in place.

The rear portions of the side guide walls are extended rearwardly of the floor 25 and are of a greater height than the remaining forward portions of the guide walls to form rear wall portions 29 interconnected by a rear backup plate or wall 30 and defining an opening 31 through the bottom of the support base.

The slider 22 is provided with guide rails 33 for fitting into the ways formed on the support base for endwise sliding movement. The bottom of the slider is provided with an elongated channel or groove 34 within which is fitted a coil compression spring 35 having an end abutted against a stop 36 formed on the forward end of the support floor 25 and an opposite rear end abutted against the end wall 37 of the groove channel (see FIG. 7). Thus, the spring resiliently urges the slider in its retracted position illustrated in FIG. 3.

The rear end of the slider is formed with a vertical slot 39 having a lower enlarged space or relief portion 40 which slot and space are defined by vertical walls 41. A cam member 42 is fitted between the walls within the vertical slot 39 and is provided with a hole 43 for alignment with holes 44 formed in the side walls through which a pivot pin 45 is inserted. .Thus, the cam member is pivotal relative to the slider.

The body of the cam member is formed as a V-shape with the apex extending rearwardly and with the V turned sideways in a horizontal direction so as to present an upper sloped cam face 46 and a lowersloped cam face 47. The cam member also includes an upwardly extending integral lever portion 48 which extends above the pivot and engages a stop shoulder 49 formed on the slider.

For moving the slider, a drive member 50 is provided (see FIG. 1). The drive member consists of a vertically elongated strip or member 51 whose upper end is fastened by a suitable bracket 52 to the press ram part and whose lower end is provided with a forwardly extending V-shaped drive cam 53.

The cam member 44 (see FIG. 7) is normally held with its lever portion abutting the stop shoulder 49. by

' a cam spring 54 arranged within a channel or groove 55 formed in the upper surface of the slider. One end of the spring is connected to a cross pin 56 arranged in the channel, which cross pin extends through pin holes 57 away from the sheet metal wall or flange. At this point, the ram of the press is moved on its 'downstroke whereby the upper die 14 in cooperation with the lower die forms the sheet metal. As shown in FIG. 7, as the ram lowers, the drive member 50 moves with it and the vertically elongated member 51 slides downwardly along the backup wall 30. The drive cam 53 engages the cam member upper sloped face 46 (see FIG. 8) causing the cam member to pivot counterclockwise (as shown in FIG. 8) against the resistance of the coil spring 54.

The drive member cam 53 then passes the apex of the cam member. During this time, the slider remains stationary, that is, in its retracted position. Also during this time, the stamping operation takes place for finally forming the sheet metal workpiece.

Upon completion of the stamping step, the ram member is now raised or retracted. During this time, the drive cam 53 raises up along with the ram, and engages the lower slopedface 47 of the cam member, rotating it back to its normal position, so that the cam member lever 48 bottoms against the stop shoulder 49 on the slider. Further upward movement of the drive cam causes relative sliding between the drive cam and the lower sloped face 47 of the cam member which is translated into a driving force to force the slider endwise so that its punch 24 engages and pierces the finished wall or flange 16 of the workpiece.

When the ram is fully retracted in its upwards position, the drive cam will be elevated above the cam member (i.e., as shown in FIG. 7) whereupon the coil spring 35 spring forces the slider back into its retracted position.

Thus, it can be seen that during the downward movement of the ram, which is the workpiece forming step, the cam member 42 is simply swung out of the way by the drive cam and the slider and punch remain inoperative. On the retraction or upwards movement of the ram, upon completion of the sheet metal forming step, the drive member now applies a force against the cam member to slide the slider and punch intooperative punching position.

Having fully described an operative embodiment of this invention, we now claim:

1. A die punch for use in a press having a press bed part for supporting a die upon which a sheet metal workpiece is die formed with a wall portion arranged approximately perpendicular to the bed part, e.g., a vertical wall portion and a horizontal bed part, and a movable press ram part, which is movable towards and away from the bed part, carrying a corresponding die for cooperative mating with the bed press die for forming such workpiece wall portion, with the die punch functioning to pierce an opening such as a hole, slot or notch in said wall portion during the retraction, that is, movement away, of the movable press ram part from the bed part after the workpiece is formed between the dies, comprising:

a punch support base arranged for fixed position mounting upon the press bed part;

a punch slider having a forward end upon which a punch element is secured, and a rear end, and means slidably mounting the punch slider upon the punch support base for slidable endwise movement relative to the punch support end, that is, back and forth slidable movement along the direction of the axis of the punch element for piercing the wall portion and for retracting therefrom;

means for forcibly moving the slider in its wall portion piercing direction, including a cam member pivotally secured to the rear end of the slider upon a pivot axised perpendicular to the direction of movement of the slider;

said cam member having a roughly V-shaped body portion with the apex of the V extending rearwardly of the slider to thereby form an upper, downwardly and rearwardly sloped face, that is, generally facing towards the movable press ram part, and a lower downwardly and forwardly sloped face, that is, generally facing towards the press bed part;

and said cam member having an integral, upper lever portion extending between said pivot and the forward edge of said cam member upper face, and said slider having a stop shoulder against which the forward edge of said lever is normally abutted;

. and a slider drive means formed of an elongated member having an end arranged for securement to the movable press ram part for movement there with, and an opposite end portion having a drive cam with a forwardly pointing V-shaped cam posi tioned to engage said cam member upper face during movement of the press ram part towards the press bed part for thereby pivotally swinging the cam member so that its lever portion moves rearwardly away from said stop shoulder portion, whereby the slider remains stationary relative to its support base, and for engaging the cam.member lower face during movement of the press rarn part away from the press bed part for therebyforcing the cam lever forwardly against the stop shoulder portion and thereby forcibly moving the slider forwardly to cause the punch element to operate against said wall portion after the wall portion is die formed. 2. A construction as defined in claim 1, and including means for rearwardly retracting said slider into a normal inoperative position upon its support base;

said means comprising a spring having one end en-' gaged with the slider and an opposite end engaged with the slider support base for spring urging the slider to its retracted position. a 3. A construction as defined in claim 1, and including a backup plate member formed upon the slider support base and spaced a short distance rearwardly of the rear end of the slider, for slidably engaging and backing the rear edge of the driver elongated. member during engagement between the drive cam and the cam member. 4. A construction as defined in claim 1, and including a spring engaged between the cam member lever portion and the slider and normally spring biasing said lever portion into contact with the slider stop portion. 5. A construction as defined in claim 1, and including at least one guide rail formed upon the slider and a co operating guide way formed upon the'slider support base for receiving said guide rail and for guiding-the sliderin its sliding movement. 

1. A die punch for use in a press having a press bed part for supporting a die upon which a sheet metal workpiece is die formed with a wall portion arranged approximately perpendicular to the bed part, e.g., a vertical wall portion and a horizontal bed part, and a movable press ram part, which is movable towards and away from the bed part, carrying a corresponding die for cooperative mating with the bed press die for forming such workpiece wall portion, with the die punch functioning to pierce an opening such as a hole, slot or notch in said wall portion during the retraction, that is, movement away, of the movable press ram part from the bed part after the workpiece is formed between the dies, comprising: a punch support base arranged for fixed position mounting upon the press bed part; a punch slider having a forward end upon which a punch element is secured, and a rear end, and means slidably mounting the punch slider upon the punch support base for slidable endwise movement relative to the punch support end, that is, back and forth slidable movement along the direction of the axis of the punch element for piercing the wall portion and for retracting therefrom; means for forcibly moving the slider in its wall portion piercing direction, including a cam member pivotally secured to the rear end of the slider upon a pivot axised perpendicular to the direction of movement of the slider; said cam member having a roughly V-shaped body portion with the apex of the V extending rearwardly of the slider to thereby form an upper, downwardly and rearwardly sloped face, that is, generally facing towards the movable press ram part, and a lower downwardly and forwardly sloped face, that is, generally facing towards the press bed part; and said cam member having an integral, upper lever portion extending between said pivot and the forward edge of said cam member upper face, and said slider having a stop shoulder against which the forward edge of said lever is normally abutted; and a slider drive means formed of an elongated member having an end arranged for securement to the movable press ram part for movement therewith, and an opposite end portion having a drive cam with a forwardly pointing V-shaped cam positioned to engage said cam member upper face during movement of the press ram part towards the press bed part for thereby pivotally swinging the cam member so That its lever portion moves rearwardly away from said stop shoulder portion, whereby the slider remains stationary relative to its support base, and for engaging the cam member lower face during movement of the press ram part away from the press bed part for thereby forcing the cam lever forwardly against the stop shoulder portion and thereby forcibly moving the slider forwardly to cause the punch element to operate against said wall portion after the wall portion is die formed.
 2. A construction as defined in claim 1, and including means for rearwardly retracting said slider into a normal inoperative position upon its support base; said means comprising a spring having one end engaged with the slider and an opposite end engaged with the slider support base for spring urging the slider to its retracted position.
 3. A construction as defined in claim 1, and including a backup plate member formed upon the slider support base and spaced a short distance rearwardly of the rear end of the slider, for slidably engaging and backing the rear edge of the driver elongated member during engagement between the drive cam and the cam member.
 4. A construction as defined in claim 1, and including a spring engaged between the cam member lever portion and the slider and normally spring biasing said lever portion into contact with the slider stop portion.
 5. A construction as defined in claim 1, and including at least one guide rail formed upon the slider and a cooperating guide way formed upon the slider support base for receiving said guide rail and for guiding the slider in its sliding movement. 